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//
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package org.apache.doris.nereids.processor.post;

import org.apache.doris.nereids.CascadesContext;
import org.apache.doris.nereids.properties.DistributionSpecGather;
import org.apache.doris.nereids.trees.plans.Plan;
import org.apache.doris.nereids.trees.plans.physical.PhysicalDistribute;
import org.apache.doris.nereids.trees.plans.physical.PhysicalLimit;

/**
 * Offset just can be in exchangeNode.
 * So, `offset` action is after `limit` action.
 * So, `limit` should update with `offset + limit`
 */
public class AddOffsetIntoDistribute extends PlanPostProcessor {
    @Override
    public Plan visitPhysicalLimit(PhysicalLimit<? extends Plan> limit, CascadesContext context) {
        limit = (PhysicalLimit<? extends Plan>) super.visit(limit, context);
        if (limit.getPhase().isLocal() || limit.getOffset() == 0) {
            return limit;
        }

        return new PhysicalDistribute<>(DistributionSpecGather.INSTANCE,
                limit.withLimit(limit.getLimit() + limit.getOffset())).copyStatsAndGroupIdFrom(limit);
    }
}
